diff --git a/include/polarssl/config.h b/include/polarssl/config.h
index ca0c176..f4f5f77 100644
--- a/include/polarssl/config.h
+++ b/include/polarssl/config.h
@@ -279,6 +279,18 @@
 #define POLARSSL_ECP_NIST_OPTIM
 
 /**
+ * \def POLARSSL_ECDSA_DETERMINISTIC
+ *
+ * Enable deterministic ECDSA (RFC 6979).
+ * Standard ECDSA is "fragile" in the sense that lack of entropy when signing
+ * may result in a compromise of the long-term signing key. This is avoided by
+ * the deterministic variant.
+ *
+ * Comment this macro to disable deterministic ECDSA.
+ */
+#define POLARSSL_ECDSA_DETERMINISTIC
+
+/**
  * \def POLARSSL_KEY_EXCHANGE_PSK_ENABLED
  *
  * Enable the PSK based ciphersuite modes in SSL / TLS.